Before the fire brigade arrives at the scene, the fastest way for occupants to suppress a fire is by discharging water through indoor hydrant outlets equipped with electronically controlled valves or motorized valves, as these systems are designed to open automatically. The experimental results are as follows: (1) Regarding electronically controlled valve operation times, system A had the shortest activation time of 6.74 seconds after the fire signal, while system J recorded the longest time at 13.4 seconds. (2) For angle valves (older model), system A had the shortest operation time of 10.2 seconds, whereas system I recorded the longest at 17.8 seconds. (3) For angle valves (newer model), system A again had the shortest activation time of 10.2 seconds, while system I recorded the longest at 17.8 seconds. (4) For motorized valve operation times, system A had the shortest activation time of 3.81 seconds, and system I the longest at 6.55 seconds. The observed differences in operation times are attributed to the fact that angle valves require manual operation by occupants, causing delays and slower valve opening, which increases activation times. In contrast, electronically controlled valves and motorized valves operate automatically, resulting in significantly shorter activation times.
Revolving doors can impede rapid evacuation during fire emergencies due to their structural characteristics, which pose a potential hazard. This study utilized the Pathfinder simulation software to analyze and compare the Required Safe Egress Time (RSET) and occupant density based on revolving door passage speed and utilization rates under different evacuation scenarios. When both revolving doors and swing doors were operational, or when revolving doors were closed and only swing doors were used, areas with an occupant density exceeding 3 persons per square meter were observed in the entrance area. However, when revolving doors were deactivated and the width of swing doors was expanded, a reduction in RSET was observed, and no areas with an occupant density exceeding 3 persons per square meter were identified. Therefore, buildings equipped with revolving doors should acknowledge the risks associated with their use. They must ensure sufficiently wide emergency exits or implement systems that allow revolving doors to open during emergencies to facilitate efficient evacuation. Furthermore, it is crucial to establish additional regulations governing the operation and safety standards of revolving doors during emergency scenarios.
In this study, fire extinguisher system to which form fire extinguisher agents were adopted was applied to the combat vehicle crew room to apply fire extinguishing performance and acid gas safety that meet the national defense standards. As a result of evaluation and verification, the following conclusions were drawn. For standard fire sizes in the combat vehicle crew's standard model, we ignited using a mixture of Novec 1230 and Halon 1301 form extinguisher agent and released form extinguisher agent after 30 seconds to determine the fire extinguishing time. The amount of acid gas generated met the criteria in all cases. When the fire size was increased to 0.12m2 and a 2.0mm nozzle was used, all of the extinguishing time, the amount of acid gas generated, and the concentration of Novec 1230 met the criteria. Despite the more difficult conditions to extinguish the fire by making the fire larger, it was possible to confirm the extinguishing performance of the Novec 1230 form extinguisher agent and its safety against acid gas.
In this study, the time to endure after conducting a test pressure test was analyzed according to the hose development length of the household hose reel indoor fire hydrant according to the apartment area. First, when the household area is 50㎡, a household hose reel indoor fire hydrant is installed inside the bathroom, and the hose is bent in a circular shape to the farthest fire point, and the test pressure is found to be inadequate only when the hose development length is 5m. When the household area of an apartment is 84㎡. It was found that the test pressure was inappropriate only when the hose deployment length was 5m with the hose bent in a circular shape to the farthest point by installing a household hose reel indoor fire hydrant inside the bathroom. When the hose deployment length was 15m, the average experimental value was 3.9 Mpa and the water pressure resistance time was 8 min. It was found that the test pressure and holding time were suitable for all of the working pressure of 0.7 Mpa, the inner diameter of the hose 25mm and 32mm, and the hose deployment length. When the installation of the hose reel indoor fire hydrant hose was 3 Mpa, the internal diameter of the hose was 25mm, 32mm, and the length of the hose deployment were all suitable.
Due to the smoke generated during a fire in an underground parking lot, initial response is difficult, resulting in an increase in life and property damage. In this study, fire cases in underground parking lots were analyzed and the necessity of legal and institutional amendments was suggested to improve the installation of smoke removal facilities, sprinkler facilities, emergency outlet facilities, and connected water pipe facilities. First, it is necessary to improve the smoke removal facilities of apartment underground parking lots. Second, it is necessary to install wet sprinklers in underground parking lots only when it has a structure or device capable of preventing freezing. It is stipulated in a manner other than wet in the fire safety technology (NFTC 103) of sprinkler facilities. However, wet sprinklers may be installed only in places where there is no fear of freezing, or when a structure or device capable of preventing freezing has been used. Third, it is necessary to amend the "Firefighting Facility Installation and Management Act" so that the standards for installing emergency outlet facilities are not regulated according to the number of underground floors, but according to the sum of the floor areas of the underground floors.
Apartments such as those on the 29th floor are generally classified as high-rise buildings; however, they may be excluded from certain safety regulations since they do not meet the legal definition of "high-rise" buildings. According to the Korean Building Act, buildings with 30 or more floors are typically regarded as high-rise buildings, warranting specific disaster prevention and safety standards. Nevertheless, buildings between 20 and 30 floors are often excluded from high-rise building regulations, which may lead to relatively insufficient safety standards and has been identified as a "blind spot in safety management." Enhancing appropriate safety facilities and strengthening regulations for such buildings is crucial, particularly in areas such as fire prevention, evacuation planning, and fire-fighting facilities. This study compares and examines the evacuation times of designated evacuation safety zones and emergency elevators in high-rise apartments as defined by the Building Act and in buildings constructed with floors between 20 and 30 through evacuation simulations.
This study aims to analyze the forest fire risk in the Gangwon region using FlamMap, a fire behavior prediction software. The research focuses on the large-scale wildfire that occurred in Gangneung on April 11, 2023. By comparing the actual fire spread data with the simulation results, the accuracy of the FlamMap model was evaluated. The actual fire exhibited a flame length of 5 to 10 meters, with a maximum of 15 meters, while the simulation predicted a range of 3.35 to 6.10 meters. The rate of spread in the actual fire reached up to 40 meters per minute, whereas the simulation forecasted a maximum of 27 meters per minute. Fireline intensity during the first 180 minutes reached 50,000 kW/m in the actual fire, while the simulation results varied between 3,500 and 25,000 kW/m, with some sections reaching up to 50,000 kW/m. Additionally, the actual fire reached nearby residential areas within 3 hours, while the simulation estimated a time range of 503 to 720 minutes. These discrepancies highlight the need for incorporating dynamic weather data and region-specific fuel conditions in future simulations for more accurate fire predictions. The findings suggest that improvements in the simulation process could enhance fire prevention and response strategies in forest fire-prone regions like Gangwon.
지형적인 이질성이 심한 강원도, 경상북도에 집중되고 있는 대형 산불을 관리하기 위해서는 위성 영상을 활용하여 효율적이고 신속한 피해 평가를 통한 의사 결정 과정이 필수적이다. 이에 본 연구는 2022년 3월 5일에 강원도 강릉 및 동해에서 발화하여 3월 8일 19시경 진화된 대형 산불을 대상으로, dNBR을 활용한 산불 심각도 산정과 등급에 영향을 미치는 환경요인을 도출하고자 하였다. 환경요인으로는 식생 또는 연료 유형을 대표하는 정규식생지수, 수종을 구분한 임상도, 수분함양을 나타내는 정규수분지수, 지형과 관련해서는 DEM 등을 수치화한 후 산불 심각도와의 상관 관계를 분석하였다. 산불 심각도는 산불 피해 없음(Unbured)이 52.4%로 가장 넓었고, 심각도 낮음 42.9%, 심각도 보통-낮음 4.3%, 심각도 보통-높음 0.4% 순이었다. 환경요인의 경우 dNDVI, dNDWI와는 음의 상관관계를, 경사도와 는 양의 상관관계를 나타내었다. 식생과 관련해서는 산불 심각도에 영향을 미치는 것으로 분석된 dNDVI, dNDWI, 경사도 모두에서 침엽수, 활엽수, 기타의 집단간 차이가 p-value < 2.2e-16로 유의미한 것으로 분석되었다. 특히, 침엽수 와 활엽수의 차이가 명확하였는데, 강원도 지역에서 우점종인 소나무를 비롯하여 잣나무, 리기다소나무, 곰솔 등의 산불 심각도가 높아 침엽수가 활엽수에 비해 피해를 받는 것이 확인되었다.
In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.
In recent years the tunnel construction is increasing worldwide because of development of science and technology and increasing of transportation demand. Tunnels are complex structures normally rectangular cross section or semicircular and constructed to connect between different sections of roads. Because of the importance, the construction and extension of road tunnels are also continuously increasing along with the development. According to data from the Korea Expressway Corporation, the number of road tunnels, which was 1,332 in 2010, increased rapidly by about 2.1 times over 10 years to a total of 2,742 in 2020. The extension of road tunnels is also on the trend of increasing, with a total of 945 km in 2010 reaching 2,157 km in 2020. The benefits of a double-deck tunnel are emphasized, particularly in terms of construction cost and convenience. This tunnel design incorporates a central slab, dividing the tunnel into upper and lower spaces. The versatility of a double-decker tunnel is evident in its ability to accommodate various uses for both levels. For instance, the upper level can function as vehicle roads, while the lower level can be designated for train tracks. In this study, the effect of RWS and modified hydrocarbon fire curve was applied to the concrete tunnel bracket through simulation to analyze the temperature after the fire occurrence.
The seismic separation joint is an important device that absorbs vibration displacement from earthquake shock and protects fire extinguishing pipes and various utility pipes. In this study, the mechanical behavior occurring in U-typed and V-typed seismic separation joint was analyzed according to the length of the bellows, the length of the elbow straight pipe, and the open angle. As a result, as the length of the bellows increased, the stress and natural frequency decreased. In addition, as the length of the elbow straight pipe increased, the stress tended to decrease in the case of forced displacement in the vertical direction. As the open angle increased, the stress in the case of forced displacement in the left and right directions increased.
내화 구조물에서는 환기 계수, 재료 탄성 계수, 항복 강도, 열팽창 계수, 외력 및 화재 위치에서 불확실성이 관찰된다. 환기 불확실성 은 화재 온도에 영향을 미치고, 이는 다시 구조물 온도에 영향을 미친다. 이러한 온도는 재료 특성과 함께 불확실한 구조적 응답으로 이어지고 있다. 화재 시 구조적 비선형 거동으로 인해 몬테카를로 시뮬레이션을 사용하여 화재 취약성을 계산하는데, 이는 시간이 많 이 소요된다. 따라서 머신러닝 알고리즘을 활용해 화재 취약성 분석을 예측함으로써 효율성을 높이고 정확성을 확보하려는 연구가 진행되고 있다. 이 연구에서는 화재 크기, 위치, 구조 재료 특성의 불확실성을 고려하여 철골 모멘트 골조 건물의 화재 취약성을 예측 했다. 화재 시 비선형 구조 거동 결과를 기반으로 한 취약성 곡선은 로그 정규 분포를 따른다. 마지막으로 제안한 방법이 화재 취약성 을 정확하고 효율적으로 예측할 수 있음을 보여주었다.
Solenopsis invicta, known as the red imported fire ant, is an insect native to South America. This species was unintentionally introduced into Australia, New Zealand, several Asian countries, Caribbean countries, and the United States. It shows a high survival rate and settlement potential in human-habitable and non-living areas such as tropical rainforests, disturbed areas, deserts, grasslands, and roads. In Korea, invasions of red fire ants have been reported every year since 2017, and two invasions were discovered in 2023. Quarantine agency analyzing the haplotype and colony social type of S. invicta for surveillance and control. Population genetic analysis using Microsatellite Alleleic data of 66 loci to trace the origin of the invasion. Through research cooperation with the United States Department of Agriculture (USDA), we have received samples and expanded our genetic information database. This study analyzed genetic differences between 15 invasive populations and 44 reference groups. As a result of microsatellite analysis, the domestic invasive population showed a genetic structure similar to those in Guangzhou, China, and Florida, USA.
This study attempted to analyze the comparative advantage in terms of disaster safety costs in verifying the effectiveness and economic feasibility of the high-performance water-bulwark system in the pole tunnel, which was recently promoted as a part of the acceleration of vehicles. The tunnel to be analyzed was divided into a short tunnel(Anyang, Cheonggye) and a long tunnel(Suraksan, Sapaesan). As a result, it was analyzed that 25% of the improvement effect would occur if one lane was secured by applying the Water-Bulwark System. It was analyzed that this is because the time value cost, which accounts for a large proportion of the traffic congestion cost of short tunnels and pole tunnels, differs depending on the congestion time and traffic volume, not the length of the tunnel.
이 논문은 정적 재하상태에 있는 무피복 강합성보와 내화피복을 적용한 강합성보를 대상으로 화재 시 내부 온도 및 수직처짐에 대 한 내화피복의 영향을 평가한 결과를 제시한다. 열응력해석을 위한 화재하중으로는 American Society for Testing and Materials E119 의 표준화재곡선을 사용했으며, 강재거더 표면에 부착하는 내화재료의 방화효과를 구현하기 위해 외기에서 강합성보로 전달되는 열 의 전달계수를 감소시켰다. 실규모 무피복 강합성보에 대한 구조화재실험에서 내부 온도분포와 수직처짐을 측정하였고 실험 결과와 의 비교를 통해 비선형 구조화재해석 결과의 타당성을 검증하였다. 내화피복이 적용된 강합성보의 구조화재해석 결과로부터 강재거 더 표면에 내화재를 적용할 경우 동일 화재 조건에서 무피복 강합성보에 비해 내부 온도와 수직처짐이 감소함을 알 수 있었다. 또한 열 전달계수의 변화에 따른 열응력 응답으로부터 화재 시 강합성보의 온도 및 구조거동에 대한 내화피복의 영향을 제시하였다.